Road bikes today are constructed from a variety of materials, ranging from the traditional steel alloy to aluminum, titanium, magnesium and carbon fiber composites, to combinations of materials. Each of these materials has their own favorable aspect. Steel alloys are known to produce pliable frames that can be “tuned” for a particular type of riding. Aluminum frames are among the stiffer frames and are thus suitable for heavier riders or those that engage in high-energy pedaling. Titanium and carbon-fiber frames are more exotic, with better strength-to-weight ratios than steel or aluminum, but are higher in cost. The current trend among high-end frames is to use a combination of materials, such as aluminum or titanium for the main part of the frame and using carbon-fiber for the front and rear portions of the frame.
When designing race bikes, two of the most important variables are its weight and aerodynamic drag. In order to reduce wheel weight and improve aerodynamic efficiency, racing bikes have fewer spokes; a typical number is 24. In some situations, the resulting weaker wheel may not be suitable for heavier loads, landing jumps, etc., since this could cause spokes to break. To reduce both air resistance and friction on the road, tires are thin and smooth. Drop handlebars and optional handlebar extensions are combined with a raised seat post in order to put the rider in a more aerodynamic posture. However, what is lacking is reducing the drag incurred from a rider being present on the cycle.